I have been turning some wrenches in my driveway and I just came across this issue. I was wondering if anyone else has seen this and if so... what was the cause. The bike is a 2005 Hayabusa. Here it goes.
When ignition is on and the kill switch is in the on position, with the clutch is pulled in, the bike turns over and starts. Mind you, I never hit the start button to do this (hand wasn't even on the bar). The bike was is in neutral.
I did the same thing with the bike in gear and it would only turn over by pulling in the clutch lever. It gets even better!! While the bike is running, if you pull in the clutch lever, the starter kicks in. So, any time the clutch lever is pulled, the bike turns over, running or not. So anytime this guy pulls up to a stop light and pulls the clutch lever, the starter motor kicks in.
This was interesting too, when the kill switch is in the off position, the ignition key is on, and the clutch lever is pulled, the bike will turn over but not start. The bike doesn't start due to the kill switch in the off position.
I checked the side stand, neutral switch, clutch diode/turn signal relay, and starter relay. which all checked out. However, the handle bar switch has got some funky things going on. So, for the time being, I am going to focus my attention on the handle bar switch.

 

Is the starter switch stuck?

does it start in Neutral without pulling in the clutch?

It sounds like either the starter switch is stuck, or the clutch saftey switch is wired wrong and someone has it connected to the wrong spot.

 

The starter button being stuck was my first thought, but I checked that and it is all good. I completely tore down the assembly and it checked out. The starter button will not work at all. The bike can only be started with the clutch lever. I checked, double checked the clutch switch and it is functioning like it should. The only reason why the start motor is not turning continuously is because of the clutch switch. I test it and it is functioning like it should. There is a short that is completely by passing the starter switch... going to be a fun one to hunt down.

 

Was gonna say sounds like your prob is on the OTHER end of the starter switch. Something where the relay connects is fused, I bet.